Subjectively speaking, I'd say snappier overall (I can't back this up with any numbers though so I could be wrong). I think the faster SSD might have added to the snappiness as well though.
With regards to the keyboard, yes it is better than the 2016 version (2017 macbook 12") and I can live with it. I honestly love the 2ndGen Butterfly keyboards on the MBPro. For me, this is the best keyboard I've ever used in terms of the experience. I heard stories that they easily get compromised by debris and so on, so that would suck if/when that happens to me. This is the 11th Macbook I've owned, I've also used the Magic Keyboard 1 and 2 and still using the Magic Keyboard 2 at work, but I still prefer the MBPro Butterfly 2 keyboard. For my gaming PC I use the Kraken BlackWidow, I type slowest on that keyboard. I normally type at around 90-95wpm, but on this new Butterfly 2, I could reach 102wpm plus I enjoy the sound and the feel of it. I also notice that the spacing of the keys are smaller compared to the 2015 MBPro 15" that I use at work at the moment. With regards to battery life though, the 15" beats my 12" with the way I use them. With the same workload and work setup, the 15" can last up to around 6hrs of real work use but at 75% brightness, and turbo-boost disabled. The 12" Macbook i7 16gb ram lasts 5hrs+ but at 100% brightness and turbo-boost enabled. I tried disabling the Turboboost on my 12" but it slowed my unit tests down considerably, unlike on the 15" mbpro. Disabling Turboboost on my 15" Mbpro gives me around 20-30mins extra battery life, and no big difference on my unit tests so I thought disabling the turboboost is okay for my use case (from 2.1s enabled, to 2.8s disabled). The biggest battery killer on the 15" though is the screen, it will only last me 2hrs if I use 100% brightness.